Cap for cut metal orthopedic fastener

Abstract

A preferably radiopaque plastic cap is provided which is sized and shaped to facilitate placement over the cut end of a K-wire, orthopedic nail, or similar shaped device, and for frictional engagement on the device. The plastic cap completely covers the non-passivated portion of the cut metal, thereby eliminating or substantially reducing the potential for negative reaction by the surrounding tissue. Moreover, there is reduced pain to the patient when flexing muscles surrounding the ends of the fasteners, and the skin can slide over the cap without irritation or inflammation.

1 . A cap for a cut end of a nail, comprising: 
 a) a lead-in tubular portion having an inner surface which defines a first diameter;    b) an engagement tubular portion having an inner surface which defines a second diameter smaller than said first diameter; and    c) a closed end at a proximal end of said engagement portion, 
 wherein said cap is manufactured from a plastic radiopaque material.  
   
     
     
         2 . A cap according to  claim 1 , wherein: 
 said plastic is resilient.    
     
     
         3 . A cap according to  claim 2 , wherein: 
 said plastic is polyurethane.    
     
     
         4 . A cap according to  claim 1 , further comprising: 
 d) an inner protuberance provided along said inner surface of said engagement portion.    
     
     
         5 . A cap according to  claim 1 , wherein: 
 said lead-in portion is cylindrical.    
     
     
         6 . A cap according to  claim 5 , wherein: 
 said engagement portion is cylindrical.    
     
     
         7 . A cap according to  claim 6 , wherein: 
 said engagement portion is longer than said lead-in portion.    
     
     
         8 . A cap according to  claim 1 , wherein: 
 said lead-in portion defines an inner diameter of approximately 0.080-0.092 inch.    
     
     
         9 . A cap according to  claim 1 , wherein: 
 said engagement portion defines an inner diameter of approximately 0.070-0.084 inch.    
     
     
         10 . A cap according to  claim 1 , wherein: 
 said cap has a length of approximately 0.285-0.310 inch.    
     
     
         11 . A cap for a cut end of a nail, comprising: 
 a) a lead-in tubular portion having an inner surface which defines a first diameter;    b) an engagement tubular portion having an inner surface which defines a second diameter smaller than said first diameter;    c) an inner protuberance provided along said inner surface of said engagement portion and directed substantially radially inward; and    d) a closed end opposite said lead-in portion.    
     
     
         12 . A cap according to  claim 11 , wherein: 
 said cap is manufactured from a plastic radiopaque material.    
     
     
         13 . A cap according to  claim 11 , wherein: 
 said inner protuberance is a ring.    
     
     
         14 . A cap according to  claim 13 , wherein: 
 said ring has a convex outer surface.    
     
     
         15 . A cap according to  claim 11 , wherein: 
 said engagement portion has an inner surface defining a third diameter smaller than said second diameter, wherein said second diameter is provided distal of said protuberance and said third diameter is provided proximal of said protuberance.    
     
     
         16 . A cap according to  claim 11 , wherein: 
 said lead-in portion has an inner diameter of approximately 0.080-0.092 inch.    
     
     
         17 . A cap according to  claim 11 , wherein: 
 said engagement portion has an inner diameter of approximately 0.070-0.084 inch.    
     
     
         18 . A cap according to  claim 1   1 , wherein: 
 said cap has a length of approximately 0.285-0.310 inch.    
     
     
         19 . A cap for a cut end of a nail, comprising: 
 a resilient plastic cylindrically tubular element having a closed end and an inner surface, said tubular element having an inner diameter sized to be close fitting to the nail, a length at least approximately three times said inner diameter, and including an inner protuberance provided along said inner surface which frictionally engages the nail.    
     
     
         20 . A cap according to  claim 19 , wherein 
 said plastic includes a radiopaque material.    
     
     
         21 . A combination orthopedic nail and cap therefor, comprising: 
 a) a metal orthopedic nail having an end with a first diameter; and    b) a cap provided over said end of said nail, 
 said cap including a lead-in portion having an inner surface which defines a second diameter larger than said first diameter such that said lead-in portion is spaced apart from said end of said nail by a clearance, an engagement portion having an inner surface which defines a third diameter approximating said first diameter such that said engagement portion is substantially in contact with said nail, and a closed end.  
   
     
     
         22 . A combination according to  claim 21 , wherein: 
 said end of said nail is a non-passivated cut end.    
     
     
         23 . A combination according to  claim 21 , wherein: 
 said cap is manufactured from a plastic radiopaque material.    
     
     
         24 . A combination orthopedic nail and cap therefor, comprising: 
 a) a metal orthopedic nail having a first diameter and a cut end; and    b) a radiopaque cap provided over said cut end of said nail, 
 said cap including a plastic cylindrically tubular element having a closed end and an inner surface, said tubular element having an inner second diameter sized to be close fitting to the nail, a length at least approximately three times said second diameter.  
   
     
     
         25 . A method of covering an end of a metal orthopedic nail, comprising: 
 a) implanting the orthopedic nail into a bone, said nail having an exposed end;    b) providing a radiopaque plastic cap over the end of the nail; and    c) seating the end of the nail and the cap beneath the skin.    
     
     
         26 . A method according to  claim 25 , further comprising: 
 prior to placing the cap, cutting the exposed end of the nail such that providing the cap over the end of the nail provides the cap over a cut end of the nail.